[q-lang-users] Types and multiple inheritance

[John.Cowan <jc...@re...>]

As I understand it, variable references with a type guard T match only
expressions whose operators are declared in the type declaration for T
or inherited from T's supertype, if any.

Since there is no state involved with types, it's not clear to me why
types aren't permitted to inherit from multiple supertypes.  The diamond
inheritance problem would be trivial in such a situation, since one
"nil" is as good as another.

I have no particular use cases for this, but the restriction to a single
supertype seems arbitrary and un-Q-ish.

-- 
Values of beeta will give rise to dom!          John Cowan
(5th/6th edition 'mv' said this if you tried    http://www.ccil.org/~cowan
to rename '.' or '..' entries; see              jc...@re...
http://cm.bell-labs.com/cm/cs/who/dmr/odd.html)